Calcium Formate

Calcium formate is one of the soluble salts of formic acid. It has many similarities (properties and hazards) to other formates. This record contains the available information specific for calcium formate, supplemented with general information on formate salts which is applicable to calcium formate. It is available commercially in very pure form (more than 99% purity), containing trace amounts of related salts.

Formic acid, also called methanoic acid), is the simplest and has the lowest mole weight of the carboxylic acids, in which a single hydrogen atom is attached to the carboxyl group (HCOOH). If a methyl group is attached to the carboxyl group, the compound is acetic acid. It occurs naturally in the body of ants and in the stingers of bees. Functionally, it is not only an acid but also an aldehyde; it reacts with alcohols to form esters as an acid and it is easily oxidized which imparts some of the character of an aldehyde. Pure formic acid is a colorless, toxic, corrosive and fuming liquid, freezing at 8.4 C and boiling at 100.7 C. It is soluble in water, ether, and alcohol. It irritates the mucous membranes and blisters the skin. It is prepared commercially from sodium formate with the reaction of condensed sulfuric acid. Formic acid is used as a chemical intermediate and solvent, in processing textiles, leathers, electroplating, in coagulating latex rubber, and as a disinfectant.

Calcium formate is a nonchloride accelerator used to accelerate the setting time of concrete. At equal concentration, calcium formate (Ca[OOOCH] 2) is less effective in accelerating the hydration of C3S than calcium chloride and a higher dosage is required to impart the same level of acceleration as that imparted by CaCl2 (Ramachandran 1984). An evaluation study of calcium formate as an accelerating admixture conducted by Gebler (1983) indicated that the composition of cement, in particular gypsum (SO3) content, had a major influence on the compressive strength development of concretes containing calcium formate. Results showed that the ratio of C3A to SO3 should be greater than 4 for calcium formate to be an effective accelerating admixture; and that the optimum amount of calcium formate to accelerate the concrete compressive strength appeared to be 2-3% by weight of cement. Calcium nitrate and calcium thiosulfate are also considered accelerators.

Accelerating admixtures are added to concrete either to increase the rate of early strength development or to shorten the time of setting, or both. Chemical compositions of accelerators include some of inorganic compounds such as soluble chlorides, carbonates, silicates, fluosilicates, and some organic compounds such as triethanolamine.

Uses and Occurrences:
Major use in power plant flue-gas scrubbing solutions; in chrome tanning of leather; as a preservative for silage; in drilling fluids and lubricants; as a fine-ore briquet binder; as a preservative in foods and feeds.

CAS NO: 544-17-2
Molecular Formula: (HCOO)2Ca
Molecular Weight: 130.12
H.S. Code: 2915.12
Synonyms: Formic acid, calcium salt; calcium diformate; Calcoform;